The Heights - 7:188 "Say: "I can neither benefit nor harm myself except what Allah wills. Had I known the secret, I would have increased my wealth and no evil would have touched me. I am but a bearer of glad tidings and a warner to a people who believe."
Related:
The Jinn/72:21 "Say, "I am not able to do you any harm or benefit."

Prophet Jonah/10:49 "Say: "Except Allah wills, I have no power to harm or benefit even myself. Every community has a term. When their term is over, they will neither be delayed for an hour nor brought forward."

The Heights/7:188 "Say: "I can neither benefit nor harm myself except what Allah wills. Had I known the secret, I would have increased my wealth and no evil would have touched me. I am but a bearer of glad tidings and a warner to a people who believe."